How can one troubleshoot when preg_match_all returns the entire text instead of the expected result in PHP?

If preg_match_all returns the entire text instead of the expected result in PHP, it may be due to incorrect regular expression patterns or improper usage of the function. To troubleshoot this issue, double-check the regular expression pattern used in preg_match_all to ensure it matches the desired content and that the function is being used correctly. Additionally, make sure to use the correct modifiers and flags for the regular expression pattern.

// Example code snippet to troubleshoot preg_match_all returning entire text
$text = "This is a sample text with some numbers like 12345.";
$pattern = "/\d+/"; // Regular expression pattern to match numbers

if(preg_match_all($pattern, $text, $matches)) {
    print_r($matches[0]); // Output the matched numbers
} else {
    echo "No matches found.";
}